Fix Your Stuff Community Store

Repair information and guides for the iPhone 6S released by Apple on September 25, 2015. Models: A1688, A1633

2693 Questions View all

Options

Touch is unresponsive after powering down.

I have an iPhone 6S in for repair and it’s got water damage, I was told that the person turned the phone off immediately and put it in rice before bringing it to me.


When it arrived I opened it and cleaned out all the residue left behind and inspected it for shorts and other damage and there is none visible, I’ve even had the board out and under a microscope with no visible damage to the board either.

There is how-ever what appears to be a scorch mark on the rear facing camera as though it over heated some how but the camera works fine zooms, takes photos and videos.


I ordered a new screen because the old one was slightly cracked after the fall and the new screen is working perfectly how-ever when I turn off the iPhone for more than a couple seconds the touch is unresponsive.

But if I disconnect the battery and then reconnect it and turn it on the touch screen works, I can put the phone to sleep and leave it all day and the touch will work fine, upon losing battery power the problem repeats its self.


I have ordered a new battery, usb connector (because with that connected the phone boot loops if there is no battery connected) and camera.


What am I missing here, could there actually be a short somewhere or a broken ICU?


Any and all help appreciated.

Kind Regards

Mike

Answered! View the answer I have this problem too

Is this a good question?

Yes No
Score 1
Add a comment

2 Answers

Filter by:
Most Helpful Newest Oldest
Chosen Solution

Options

The Touch logic circuitry is embedded in the screen however, the power for the Touch screen still comes from the logic board. The Chestnut IC (U4000) is responsible for this power and it is located in the upper backside of the logic board. Considering you saw scorch marks near the RCAM, it is clear that water got into the upper section of the phone.

You will want to check the power rails coming out of Chestnut. They’ll probably show as fine initially but when the screen loses touch, check them again (this will require that you remove the logic board and jimmy-rig it with an external dock, battery and screen to test).

Was this answer helpful?

Yes No
Score 2

1 Comment:

Yes, you are right the ICU is playing up, I'm no good at micro soldering so I'll have to pass this over to someone else, this is my GF's son's phone I fix phones as an hobby and soldering is something I do not dare do with other peoples phones. Going have to ring around local shops see which one takes my fancy to remove the ICU for me.

Cheers for the help.

by

Add a comment

Options

It’s seems like there is short somewhere as it’s been in contact with water.

Was this answer helpful?

Yes No
Score 0
Add a comment

Add your answer

Gadget Mikes will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 1

Past 30 Days: 2

All Time: 52